Current Electricity · Physics · NEET

A certain wire $$\mathrm{A}$$ has resistance $$81 ~\Omega$$. The resistance of another wire $$\mathrm{B}$$ of same material and equal length but of di...

A copper wire of radius $$1 \mathrm{~mm}$$ contains $$10^{22}$$ free electrons per cubic metre. The drift velocity for free electrons when $$10 \mathr...

The emf of a cell having internal resistance $$1 \Omega$$ is balanced against a length of $$330 \mathrm{~cm}$$ on a potentiometer wire. When an extern...

The magnitude and direction of the current in the following circuit is :- ...

If the galvanometer $$G$$ does not show any deflection in the circuit shown, the value of $$R$$ is given by: ...

Resistance of a carbon resistor determined from colour codes is $$(22000 \pm 5 \%) \Omega$$. The colour of third band must be :

The resistance of platinum wire at $$0^{\circ} \mathrm{C}$$ is $$2 ~\Omega$$ and $$6.8 ~\Omega$$ at $$80^{\circ} \mathrm{C}$$. The temperature coeffic...

10 resistors, each of resistance $$\mathrm{R}$$ are connected in series to a battery of emf $$E$$ and negligible internal resistance. Then those are c...

The reciprocal of resistance is :

A cell of emf 4 V and internal resistance 0.5 $$\Omega$$ is connected to a 7.5 $$\Omega$$ external resistance. The terminal potential difference of th...

The equivalent resistance of the infinite network given below is : ...

The sliding contact C is at one fourth of the length of the potentiometer wire (AB) from A as shown in the circuit diagram. If the resistance of the w...

Two resistors of resistance, 100 $$\Omega$$ and 200 $$\Omega$$ are connected in parallel in an electrical circuit. The ratio of the thermal energy dev...

A copper wire of length 10 m and radius $$\left( {{{{{10}^{ - 2}}} \over {\sqrt \pi }}} \right)$$ m has electrical resistance of 10 $$\Omega$$. The c...

A wheatstone bridge is used to determine the value of unknown resistance X by adjusting the variable resistance Y as shown in the figure. For the most...

In a potentiometer circuit a cell of EMF 1.5 V gives balance point at 36 cm length of wire. If another cell of EMF 2.5 V replaces the first cell, then...

The effective resistance of a parallel connection that consists of four wires of equal length, equal area of cross-section and same material is 0.25$$...

Column - I gives certain physical terms associated with flow of current through a metallic conductor. Column-II gives some mathematical relations invo...

Three resistors having resistances r1, r2 and r3 are connected as shown in the given circuit. The ratio $${{{i_3}} \over {{i_1}}}$$ of currents in ter...

A resistance wire connected in the left gap of a metre bridge balances a 10 $$\Omega $$ resistance in the right gap at a point which divides the brid...

The color code of a resistance is given below : The values of resistance and tolerance, respectively, are...

A charged particle having drift velocity 7.5$$ \times $$10-4 ms-1 in an electric field of 3$$ \times $$10-10 Vm-1 has a mobility in m2 V-1s-1 of :...

Which of the following graph represents the variation of resistivity ($$\rho $$) with temperature (T) for copper?

The solids which have the negative temperature coefficient of resistance are :

Six similar bulbs are connected as shown in the figure with a DC source of emf E, and zero internal resistance. The ratio of power consumption by th...

In the circuits shown below, the readings of voltmeters and the ammeters will be : ...

Which of the following acts as a circuit protection device?

A battery consists of a variable number n of identical cells (having internal resistance r each) which are connected in series. The terminals of the b...

A carbon resistor of (47 $$ \pm $$ 4.7) k$$\Omega $$ is to be marked with rings of different colours for its identification. The colour code sequence ...

A set of n equal resistors, of value R each, are connected in series to a battery of emf E and internal resistance R. The current drawn is I. Now, the...

The resistance of a wire is 'R' ohm. If it is melted and stretched to 'n' times its original length. its new resistance will be

A potentiometer is an accurate and versatile device to make electrical measurements of EMF because the method involves

The potential difference (VA $$-$$ VB) between the points A and B in the given figure is ...

A filament bulb (500 W, 100 V) is to be used in a 230 V main supply. When a resistance R is connected in series, it works perfectly and the bulb consu...

A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support on...

The charge flowing through a resistance R varies with time t is Q = at $$-$$ bt2, where $$a$$ and $$b$$ are positive constants. The total heat produce...

Two metal wires of identical dimensions are connected in series. If $$\sigma $$1 and $$\sigma $$2 are the conductivity of the combination is ...

A circuit contains an ammeter, a battery of 30 V and a resistance 40.8 ohm all connected in series. If the ammeter has a coil of resistance 480 ohm ...

A potentiometer wire of length L and a resistance r are connected in series with a battery of e.m.f. E0 and a resistance r1. An unknown e.m.f. E is ba...

Across a metallic conductor of non-uniform cross section a constant potential difference is applied. The quantity which remains constant along the con...

A, B and C are voltmeters of resistance R, 1.5 R and 3R respectively as shown in the figure. When some potential difference is applied between X and Y...

A potentiometer wire has length 4 m and resistance 8 $$\Omega $$. The resistance that must be connected in series with the wire and an accumulator of ...

The resistances in the two arms of the meter bridge are 5 $$\Omega $$ and R$$\Omega $$ respectively. When the resistance R is shunted with an equal re...

A potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has...

Two cities are 150 km apart. Electric power is sent from one city to another city through copper wires. The fall of potential per km is 8 volt and t...

Two rods are joined end to end, as shown. Both have a cross-sectional area of 0.01 cm2. Each is 1 meter long. One rod is of copper with a resistivity ...

A 12 cm wire is given a shape of a right angled triangle ABC having sides 3 cm, 4 cm and 5 cm as shown in the figure. The resistance between two ends ...

Ten identical cells connected in series are needed to heat a wire of length one meter and radius 'r' by 10oC in time 't'. How many cells will be requi...

The resistances of the four arms P, Q, R and S in a Wheatstone's bridge are 10 ohm, 30 ohm, 30 ohm and 90 ohm, respectively. The e.m.f. and internal r...

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 $$\Omega $$ is

A wire of resistance 4 $$\Omega $$ is stretched to twice its original length. The resistance of stretched wire would be

A cell having an emf $$\varepsilon $$ and internal resistance r is connected across a variable external resistance R. As the resistance R is increased...

The power dissipated in the circuit shown in the figure is 30 watts. The value of R is ...

In the circuit shown the cells A and B have negligible resistances. For VA = 12 V, R1 = 500 $$\Omega $$ and R = 100 $$\Omega $$ the galvanometer (G) ...

A ring is made of a wire having a resistance R0 = 12 $$\Omega $$. Find the points A and B, as shown in the figure, at which a current carrying conduct...

If voltage across a bulb rated 220 volt-100 watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease...

In the circuit shown in the figure, if the potential at point A is taken to be zero, the potential at point B is ...

A thermocouple of negligible resistance produces an e.m.f. of 40 µV/ºC in the linear range of temperature. A galvanometer of resistance 10 ohm whose s...

A current of 2 A flows through a 2 $$\Omega $$ resistor when connected across a battery a 2 $$\Omega $$ resistor when connected across a battery. The ...

If power dissipated in the 9 $$\Omega $$ resistor in the circuit shown is 36 watt, the potential difference across the 2 $$\Omega $$ resistor is ...

Consider the following two statements. (A)  Kirchoff's junction law follows from the conservation of charge. (B)  Kirchhoff's lo...

A potentiometer circuit is set up as shown. The potential gradient, across the potentiometer wire, is k volt/cm and the ammeter, present in the circui...

See the electrical circuit shown in this figure. Which of the following equations is a correct equation for it ? ...

A wire of resistance 12 ohms per meter is bent to form a complete circle of radius 10 cm. The resistance between its two diametrically opposite points...

The mean free path of electrons in a metal is 4 $$ \times $$ 10$$-$$8 m. The electric field which can give on an average 2 eV energy to an electron in...

A student measures the terminal potential difference (V) of a cell (of emf $$\varepsilon $$ and internal resistance r) as a function of the current (I...

In the circuit shown, the current through the 4 $$\Omega $$ resistor is 1 amp when the points P and M are connected to a d.c. voltage source. The pot...

A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively

A current of 3 amp. flows through the 2 $$\Omega $$ resistor shown in the circuit. The power dissipated in the 5 $$\Omega $$ resistor is ...

A cell can be balanced against 110 cm and 100 cm of potentiometer wire, respectively with and without being short circuited through a resistance of 10...

An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature 20oC ? The temperature of boiling wat...

The total power dissipated in watt in the circuit shown here is ...

Three resistances, P, Q, R each of 2$$\Omega $$ and an unknown resistance S from the four arms of a Wheatstone bridge circuit. When a resistance of 6 ...

In the circuit shown, if a conducting wire is connected between points A and B, the current in this wire will ...

Two cells, having the same e.m.f. are connected in series through an external resistance R. Cells have internal resistances r1 and r2 (r1 > r2) res...

Kirchoff's first and second laws of electrical circuits are consequences of

Power dissipated across the 8 $$\Omega $$ resistor in the circuit shown here is 2 watt. The power dissipated in watt units across the 3 $$\Omega $$ re...

Two batteries, one of emf 18 volts and internal resistance 2 $$\Omega $$ and the other of emf 12 volts and internal resistance 1 $$\Omega $$, are conn...

A 5-ampere fuse wire can withstand a maximum power of 1 watt in the circuit. The resistance of the fuse wire is

For the network shown in the figure the value of the current $$i$$ is ...

When a wire of uniform cross-section $$a$$ length $$l$$ and resistance R is bent into a complete circle. resistance between any two of diametrically o...

Five equal resistances each of resistances R are connected as shown in the figure. A battery of V volts is connected between A and B. The current flow...

when three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be

A 6 volt battery is connected to the terminals of a three metre long wire of uniform thickness and resistance of 100 ohm. The difference of potential...

In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, th...

Resistance n, each of r ohm, when connected in parallel give an equivalent resistance of R ohm. If these resistances were connected in series, the co...

The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then

Two 220 volt, 100 watt bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220 volt a.c. supply lin...

An electric kettle has two heating coils. When one of the coils is connected to an a.c. source, the water in the kettle boils in 10 minutes. When the ...

Fuse wire is a wire of

In a Wheatstone's bridge all the four arms have equal resistance R. If the resistance of the galvanometer arm is also R, the equivalent resistance of ...

For a cell terminal potential difference is 2.2V when circuit is open and reduce to 1.8 V when cell is connected to a resistance of R = 5 $$\Omega $$....

Specific resistance of a conductor increases with

Copper and silicon is cooled from 300 K to 60 K , the specific resistance

The resistance of each arm of the Wheatstone's bridge is 10 ohm. A resistance of 10 ohm is connected in series with a galvanometer then the equivalent...

If specific resistance of a potentiometer wire is 10-7$$\Omega $$ m and current flow through it is 0.1 amp., cross-sectional area of wire is 10$$-$$6 ...

Two bulbs of (40 W, 200 V), and (100 W, 200 V). Then correct relation for their resistances

The net resistance of the circuit between A and B is ...

A car battery of emf 12 V and internal resistance $$5 \times {10^{ - 2}}$$ $$\Omega $$., receives a current of 60 amp, from external source, then term...

The potentiometer is best for measuring voltage, as